<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    .loading {
      width: 160px;
      height: 160px;
      margin: 50px auto;
      position: relative;
      background-color: #fff;
      border-radius: 50%;
      border: 1px solid #ccc;
      text-align: center;
      line-height: 160px;
      box-sizing: border-box;
    }

    .loading::before {
      content: '';
      position: absolute;
      width: 220px;
      height: 220px;
      border-radius: 50%;
      background-color: skyblue;
      border: 1px solid #eee;
      left: -31px;
      top: -31px;
      z-index: -1;
      box-sizing: border-box;
      clip-path: polygon(50% 0, 100% 0, 100% 50%, 50% 50%);
      animation-name: rotate;
      animation-duration: 1s;
      animation-timing-function: linear;
      animation-iteration-count: infinite;
    }

    .loading::after {
      content: '';
      position: absolute;
      width: 220px;
      height: 220px;
      border-radius: 50%;
      background-color: #fafafa;
      border: 1px solid #eee;
      left: -31px;
      top: -31px;
      z-index: -2;
      box-sizing: border-box;
    }

    @keyframes rotate {
      from {
        transform: rotate(0deg);
      }

      to {
        transform: rotate(360deg);
      }
    }
  </style>
</head>

<body>
  <div class="loading">loading...</div>
</body>

</html>